Senior police sources have slammed his appointment as 'mere public relations' by the new Government of Prime Minister Chuan Leekpai.

And others are warning of problems if he comes on too strong.

General Seri faced a host of internal threats during his last tenure under the rule of prime minister General Chatichai Choonhavan.

They included the planting of a bomb in his office as he sought to end decades of police corruption.

'I will replace muddy water with clean water until the whole lake is clean,' he vowed shortly after the attack.

He was ousted in the 1991 coup against General Chatichai's regime but returned under the Democrats two years later to take on top gangsters and political figures linked to vote-buying in cases still being probed.

'His aggressiveness can be his weakness,' one leading officer once said of General Seri's high-profile drives against graft.

'Men can be killed, but not insulted.' Democrat Party officials said his nomination was a key part of efforts to ensure Thailand's sweeping new constitution was implemented.

The charter, which has been approved by King Bhumibol Adulyadej, seeks to end political patronage and create a cleaner, more transparent police force.

While they try to pull Thailand out of its worst economic crisis since World War II, the Democrats must also live up to sweeping promises to support the charter set to create a framework for elections next year.